A thin film transistor liquid crystal display (TFT-LCD) driver mainly comprises a gate driving circuit and a data driving circuit, wherein the gate driving circuit applies an input clock signal to a gate line of a liquid crystal display panel after having converted the input clock signal through a shift register unit, and the gate driving circuit can have the same process as the TFT and form together with the TFT on the LCD panel simultaneously. The gate driving circuit comprises shift register units having multiple stages, each of which is connected to a corresponding gate line to output a gate driving signal. Respective stages of gate driving circuit are connected with each other, and a start signal is input to a first stage of the respective stages and the gate driving signal is sequentially output to the gate line, wherein an input terminal of the present stage is connected to an output terminal of the previous stage, and an output terminal of the next stage is connected to a control terminal of the present stage.
The gate driving circuit of the above configuration is set on the LCD panel, and its each stage of shift register unit comprises the structure as shown in FIG. 1. However, the gate driving circuit composed of the shift register unit as shown in FIG. 1 is of high power consumption and easily causes noise. Besides, after the multiple stages are connected, the gate driving circuit needs up and down two virtual shift register units to operate normally. In general, the design structure and signal input of the two virtual shift register units differs from the structure of other shift register units in the circuit, and it is needed to add signal lines to provide signals for the virtual shift register units, which finds more difficulty in the wiring and increases the signal output of the gate driving circuit, thereby increasing the power consumption of the gate driving circuit.